The effect of glycemic control on visual and anatomic outcomes in response to therapy for diabetic macular edema

Purpose. To evaluate the effect of glycemic control on response to therapy of diabetic clinically significant macular edema (CSME). Methods. Patients with CSME had their glycosylated hemoglobin (HbA1c) measured at baseline and 6 months. Central foveal thickness (CFT) and best-corrected visual acuity (BCVA) in logMAR were measured at baseline, 3 months, and 6 months. Therapy included laser and intravitreal bevacizumab. HbA1c was graded as G1 <7%, G23 7%-7.9%, G3 8%-8.9%, G4 >9%. Results. Fifty-two eyes were included with mean logMAR BCVA and CFT as follows: baseline 0.75 and 423±106 µm; 3 months 0.47 and 293±69 µm; and 6 months 0.48 and 324±76 µm. Mean HbA1c was 8.13% and 7.43% at baseline and 6 months, respectively. There was no statistically significant difference between baseline and 6 months HbA1c groups and logMAR BCVAs and CFTs at baseline, 3 months, and 6 months. However, there were positive correlations between baseline HbA1c levels and each of baseline logMAR BCVA (p=0.024), baseline CFT (p<0.001), and 6-month logMAR BCVA (p=0.007). Improved HbA1c by 6 months did not show any correlation with logMAR BCVA and CFT at 6 months. Conclusions. Lower HbA1c appeared to be correlated with better visual acuity and lower CFT values at baseline, and also correlated with significantly better vision and nonsignificantly thinner CFT with therapy at 6 months.